Patents by Inventor John Marcus Hart, Jr.

John Marcus Hart, Jr. has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5867886
    Abstract: A media-compatible, high-pressure transducer cell (12), a rugged sensor assembly (10) incorporating the cell (12), and a method for its production. The pressure cell (12) generally includes a metal body having a diaphragm (26), at least one dielectric layer (28, 38) on the diaphragm (26), and at least one thick-film piezoresistive element (34) on the dielectric layer (28, 38) for sensing deflection of the diaphragm (26). For purposes of compatibility with a wide variety of media, the metal body is preferably formed of steel, most preferably a stainless steel alloy such as an AISI Type 300 or 400 Series. The diaphragm (26) can be formed by etching or machining the metal body. The dielectric layers (28, 38) are preferably formed by thick-film processing as done for the piezoresistive element (34), employing materials that will adhere to the metal diaphragm (26), withstand the strains induced as the diaphragm (26) deflects, and faithfully transmit such strains to the thick-film piezoresistor (34).
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: February 9, 1999
    Assignee: Delco Electronics Corp.
    Inventors: Joseph Martin Ratell, John Marcus Hart, Jr.